CD74-ROS1 fusion transcripts in resected non-small cell lung carcinoma

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Fusion oncokinases in non-small cell lung cancer (NSCLC) are clinically significant due to their sensitivity to kinase inhibitors.
• ROS1 and RET fusion oncokinases are recently identified targets in pulmonary carcinogenesis.

Purpose of the Study:

• To investigate the prevalence and characteristics of SLC34A2-ROS1, EZR-ROS1, CD74-ROS1, and KIF5B-RET fusion transcripts in 114 NSCLC cases.
• To understand the role of these fusions in the development of lung cancer.

Main Methods:

• RT-polymerase chain reaction and sequencing were used to detect fusion transcripts.
• Immunohistochemistry was employed to assess ROS1 protein expression.
• Mutation analysis of KRAS, EGFR, BRAF, PIK3CA, and p53 genes was performed.

Main Results:

• CD74-ROS1 fusion transcripts were detected in one (0.9%) of 114 NSCLCs.
• The fusion was an in-frame alteration between CD74 exon 6 and ROS1 exon 34.
• ROS1 protein overexpression was observed in cancer tissues, and no mutations were found in common oncogenes or p53.

Conclusions:

• The CD74-ROS1 fusion is implicated in the carcinogenesis of a subset of NSCLCs.
• This finding contributes to characterizing ROS1 fusion-positive NSCLC.
• Further research into ROS1 fusion-positive NSCLC is warranted.